/*
 * Copyright 2021 ZhongChao Blockchain Technology Research Institute.
 *
 * Copyright ConsenSys AG.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 *
 * This file has been modified by ZhongChao Blockchain Technology Research Institute to add support for Brochain.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

package link.luyu.plugin.brochain.trie;

import java.util.function.BiConsumer;
import org.apache.tuweni.bytes.Bytes;
import org.apache.tuweni.bytes.Bytes32;

public class PersistVisitor<V> implements NodeVisitor<V> {

    private int branchNodeCount = 0;
    private int extensionNodeCount = 0;
    private int leafNodeCount = 0;

    private final BiConsumer<Bytes32, Bytes> writer;

    public PersistVisitor(final BiConsumer<Bytes32, Bytes> writer) {
        this.writer = writer;
    }

    public Node<V> initialRoot() {
        return NullNode.instance();
    }

    public void persist(final Node<V> root) {
        if (root instanceof BranchNode) {
            visit((BranchNode<V>) root);
        } else if (root instanceof ExtensionNode) {
            visit((ExtensionNode<V>) root);
        } else if (root instanceof LeafNode) {
            visit((LeafNode<V>) root);
        } else if (root instanceof NullNode) {
            visit((NullNode<V>) root);
        }
    }

    @Override
    public void visit(final BranchNode<V> branchNode) {
        writer.accept(branchNode.getHash(), branchNode.getRlp());
        branchNodeCount++;
        branchNode.getChildren().forEach(node -> node.accept(this));
    }

    @Override
    public void visit(final ExtensionNode<V> extensionNode) {
        writer.accept(extensionNode.getHash(), extensionNode.getRlp());
        extensionNodeCount++;
        extensionNode.getChild().accept(this);
    }

    @Override
    public void visit(final LeafNode<V> leafNode) {
        writer.accept(leafNode.getHash(), leafNode.getRlp());
        leafNodeCount++;
    }

    @Override
    public void visit(final NullNode<V> nullNode) {}

    public int getBranchNodeCount() {
        return branchNodeCount;
    }

    public int getExtensionNodeCount() {
        return extensionNodeCount;
    }

    public int getLeafNodeCount() {
        return leafNodeCount;
    }
}
